System size and energy dependence of near-side dihadron correlations
rticle azimuthal (Δφ) and pseudorapidity (Δη) correlations using a trigger particle with large transverse momentum (pT) in d+Au, Cu+Cu, and Au+Au collisions at √sNN = 62.4 GeV and 200 GeV from the STAR experiment at the Relativistic Heavy Ion Collider are presented. The near-side correlation is sepa...
| Main Authors: | , , , , , , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Physical Society
2012
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| Online Access: | http://hdl.handle.net/1721.1/72138 https://orcid.org/0000-0002-5515-4563 https://orcid.org/0000-0001-5839-707X https://orcid.org/0000-0002-9107-6312 |
| Summary: | rticle azimuthal (Δφ) and pseudorapidity (Δη) correlations using a trigger particle with large transverse momentum (pT) in d+Au, Cu+Cu, and Au+Au collisions at √sNN = 62.4 GeV and 200 GeV from the STAR experiment at the Relativistic Heavy Ion Collider are presented. The near-side correlation is separated into a jet-like component, narrow in both Δφ and Δη, and the ridge, narrow in Δφ but broad in Δη. Both components are studied as a function of collision centrality, and the jet-like correlation is studied as a function of the trigger and associated pT. The behavior of the jet-like component is remarkably consistent for different collision systems, suggesting it is produced by fragmentation. The width of the jet-like correlation is found to increase with the system size. The ridge, previously observed in Au+Au collisions at √sNN = 200 GeV, is also found in Cu+Cu collisions and in collisions at √sNN = 62.4 GeV, but is found to be substantially smaller at √sNN = 62.4 GeV than at √sNN = 200 GeV for the same average number of participants (〈Npart〉). Measurements of the ridge are compared to models. |
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